The binary operation given is defined by;
[tex]\begin{gathered} x\oint y=2x-3y \\ \end{gathered}[/tex][tex]\begin{gathered} x+x\oint y\text{ will be defined by} \\ x+(2x-3y) \\ \text{when x = 3 and y = -5} \\ x+(2x-3y)=3+(2(3)-3(-5)) \\ =3+(6+15) \\ =3+6+15 \\ =24 \end{gathered}[/tex]Therefore, the answer to the operation is 24.
